Chapter 1
Exploring Life
introduction to Biology
Chapter 1: Exploring Life
Dr. Nezar Redwan
‫‪Introduction: Getting Acquainted with Biology‬‬
‫مدخل ‪ :‬التعريف بعلم الحياة‬
‫تعريف المصطلــــــــــح‬
‫علم الحياة هو علم دراسة ظاهرة الحياة ممثلة في النبات‬
‫والحيوان والكائنات الدقيقة وكذا اإلنسان‬
‫علم األحياء هو الدراسة العلمية للحياة‬
‫مصطلح ”‪ “Biology‬مشتق من كلمتين يونانيتين ‪:‬‬
‫‪Bios‬يعني حياة و ‪ Logos‬يعني علـــم‬
‫الكائنات الحية‬
‫التكيف وهي التهيؤ واالستعداد الفطري للكائن الحي للعيش‬
‫تحت ظروف بيئته التي يوجد فيها‬
‫التطور هو عملية التغير المفطور عليها الكائن التي يكيف‬
‫بها حياته ويحورها‬
‫التعضية صفة أخرى هامة للكائنات الحية بها تحدد‬
‫موضوعات الدراسة في علم األحياء‬
‫التنظيم الهرمي للحياة‬
‫صفات جديدة تعرف بالصفات الناشئة‬
‫الغالف الجوي – كل البيئات (األنظمة البيئية) الداعمة‬
‫للحياة على األرض‬
‫‪Dr. Nezar Redwan‬‬
‫المصطلـــــــــــــــــــــــــــــــــح‬
‫‪Biology Is The Science Of Life In All Its‬‬
‫‪Living Forms, Plants, Animals And‬‬
‫‪Microorganisms Including Man‬‬
‫‪Biology Is The Scientific Study Of Life‬‬
‫= ‪The Term “Biology” Derived From Bios‬‬
‫‪Life And Logos = Science Logos‬‬
‫‪Living Organisms‬‬
‫‪Adaptation‬‬
‫‪Evolution‬‬
‫‪Organization‬‬
‫‪Hierarchy Of Life‬‬
‫‪Emergent Properties‬‬
‫‪Biosphere‬‬
‫‪Chapter 1: Exploring Life‬‬
‫النظام البيئي – كل الجماعات من الكائنات المختلفة التي‬
‫تعيش في منطقة معينة‬
‫الجماعة – كل الكائنات المختلفة (العشائر المختلفة) التي‬
‫تعيش في نظام بيئي معين‬
‫العشيرة – كل أفراد النوع الواحد يتزاوجون فيما بينهم فقط‬
‫في منطقة معينة‬
‫األجهزة العضوية – لها وظائف محددة وتتألف من أعضاء‬
‫األعضاء – تؤدي وظائف محددة للكائن‬
‫األنسجة – مكونة من مجموعة من الخاليا المتشابهة‬
‫جزيئات – تجمع من الذرات‬
‫عضيات – تراكيب غشائية ذات وظائف محددة‬
‫خاليا – كيانات حية تفترق بغشاء عن بيئتها‬
‫المكونات الحية والغير الحية‬
‫الكائنات القادرة على البناء الضوئي‬
‫ال ُمنتجات توفر الغذاء‬
‫بال ُمستهلكات‬
‫كائنات تتغذى على النباتات ( أو على حيوانات تتغذى على‬
‫النباتات )‬
‫المكونات غير الحية عبارة عن مواد غذائية كيميائية‬
‫ضرورية للحياة‬
‫‪Dr. Nezar Redwan‬‬
‫‪Ecosystem‬‬
‫‪Community‬‬
‫‪Population‬‬
‫‪Organ Systems‬‬
‫‪Organs‬‬
‫‪Tissues‬‬
‫‪Molecules‬‬
‫‪Organelles‬‬
‫‪Cells‬‬
‫‪Living And Nonliving Components‬‬
‫‪Photosynthetic Organisms‬‬
‫‪Producers Are Called And Provide Food‬‬
‫‪Consumers‬‬
‫‪The Nonliving Components‬‬
‫‪Chapter 1: Exploring Life‬‬
Recycle Chemicals
Necessary For Life
Move Energy Through The Ecosystem
Prokaryotic Cells
Genetic Material Is Not Surrounded By A
Nuclear Membrane
Simple And Small
Bacteria Are Prokaryotic
Eukaryotic Cells
Possess Organelles Separated By Membranes
Plants, Animals, And Fungi Are Eukaryotic
Nucleus
Contains DNA Surrounded By Nuclear
Membrane
Membrane
DNA Is The Genetic (Hereditary) Material Of
All Cells
A Gene Is A Discrete Unit Of DNA
Chapter 1: Exploring Life
‫إعادة تدوير الكيماويات‬
‫تحريك الطاقة خالل النظام البيئي‬
‫خاليا أولية النواة‬
‫المادة الوراثية غير محاطة بغالف نووي‬
‫صغيرة وبسيطة‬
‫البكتيريا أولية النواة‬
‫خاليا حقيقية النواة‬
‫تمتلك عضيات محاطة بأغشية تفصلها عن السيتوبالزم‬
‫النباتات والحيوانات والفطريات حقيقية النواة‬
‫نواة‬
‫تحتوي على دنا محاط بغالف نووي‬
‫غشاء‬
‫الدنا هو المادة الوراثية لكل الخاليا‬
‫الجين عبارة عن وحدة مميزة من الدنا‬
Dr. Nezar Redwan
‫النظام – التعضي المعقد للكائنات الحية‬
‫التنظيم – المقدرة على المحافظة على بيئة داخلية متناسقة‬
‫مع الحياة‬
‫النمو والتطور الجنيني‬
‫معالجة الطاقة – إكتساب الطاقة وتحويلها لصورة نافعة‬
‫للكائن بممارسة األيض‬
‫االستجابة للبيئة – قدرة االستجابة للمؤثرات البيئي‬
‫التكاثر – المقدرة على إكثار النوع‬
‫التكيف التطوري – اكتساب الصفات األكثر تناسبا للكائن‬
‫مع بيئته‬
‫عوالـــم‬
‫هناك ثالث عوالم ( مجاميع ) حيوية‬
‫البكتيريا – أولية النواة ‪ ،‬وعادة ما تكون وحيدة الخلية و‬
‫مجهرية‬
‫البدائيات – أولية النواة ‪ ،‬وعادة ما تكون وحيدة الخلية و‬
‫مجهرية شأنها شأن البكتيريا‬
‫حقيقيات النواة – خاليا حقيقية النواة أي لها نواة و‬
‫عضيات‬
‫‪Dr. Nezar Redwan‬‬
‫‪Order‬‬
‫‪Regulation‬‬
‫‪Growth And Development‬‬
‫‪Energy Processing‬‬
‫‪Response To The Environment‬‬
‫‪Reproduction‬‬
‫‪Evolutionary Adaptation‬‬
‫‪Domains‬‬
‫‪The Three Domains (Groups) Of Life‬‬
‫‪Bacteria - Prokaryotic, And Most Are‬‬
‫‪Unicellular And Microscopic‬‬
‫‪Archaea - Like Bacteria, Are Prokaryotic,‬‬
‫‪And Most Are Unicellular And Microscopic‬‬
‫‪Eukarya - Are Eukaryotic And Contain A‬‬
‫‪Nucleus And Organelles‬‬
‫‪Chapter 1: Exploring Life‬‬
‫الطريقة العلمية‬
‫العلم االستقرائي – يستخدم مشاهدات وقياسات متنوعة‬
‫لوصف العلم‬
‫العلم االفتراضي (اإلستنتاجي – اإلستداللي) – يستخدم‬
‫البيانات الذي يوفرها العلم االستقرائي وذلك لوضع‬
‫تفسيرات علمية (إنه العلم التجريبي)‬
‫الفرضية هي تفسير مقترح لمجموعة من المشاهدات‬
‫وبمعنى آخر هي اإلجابة التخمينية لألسئلة التي تثيرها‬
‫المشاهدة‬
‫النظرية هي إستنتاج علمي مبني على التجربة مؤيد‬
‫بعدد كبير ومتزايد من األدلة المدعومة بالتجارب‬
‫‪Dr. Nezar Redwan‬‬
‫‪THE PROCESS OF SCIENCE‬‬
‫‪Discovery Science‬‬
‫‪Hypothesis- Based Science‬‬
‫‪A Hypothesis‬‬
‫‪A Theory‬‬
‫‪Chapter 1: Exploring Life‬‬
Topics Discussed in this chapter
1. The Characteristics of Life
2. Biological Organization
3. The 3 domains of life
4. Steps in the Scientific Method
Chapter 1: Exploring Life
Dr. Nezar Redwan
What is Biology?
Biology is the study of all living things
 Living things are called organisms
Organisms include bacteria, protists,
fungi, plants, & animals
Chapter 1: Exploring Life
Dr. Nezar Redwan
Biology:
is the scientific study of life in all its living
forms, plants, animals and microorganisms
including man
The term “Biology” derived from
bios = life
and
logos = science
Chapter 1: Exploring Life
Dr. Nezar Redwan
All Living Things Share
Common Characteristics
known as:
The Characteristics of Life
Chapter 1: Exploring Life
Dr. Nezar Redwan
The Characteristics of Life
1. Order(organization) :
Living organisms are organized in several levels of
increasing complexity best described as a :
Hierarchy of life levels.
Atoms
Molecules
Cells – life starts here
Tissues
Organs
Organelles
Organism
Population
Community
Ecosystem
Biosphere
Chapter 1: Exploring Life
System
Dr. Nezar Redwan
Biosphere
Life’s hierarchy of organization
Ecosystem
‫جميع العشائر المختلفة المتفاعلة مع ما يحيط‬
‫بها من ماء وهواء وتربة ومناخ في منطقة‬
Florida coast ‫معينة مثل ساحل فلوريدا‬
Community, All organisms on
the Florida coast
‫ال‬
Population, Group
of brown pelicans
Organism
Brown pelican
Spinal cord
Organ system
Nervous system
Nerve
Brain
‫ا‬
Organ ‫ا‬
Brain
Tissue
Nervous tissue
Cell
Nerve cell
Nucleus
‫ا‬
Organelle
Nucleus‫ن‬
Molecule
DNA
Atom
‫ذرة‬
Organism
Population
Organ system
Organ
Tissue
Cell
Community
Bone cells
Nucleus
Organelle
Ecosystem
Macromolecule
Molecule
Biosphere
Oxygen atom
Hydrogen atoms
Water
Hierarchy of life levels.
 Atom
 Molecules - clusters of atoms
 Organelles - membrane-bound structures with different jobs
inside Cells
 Cells - life starts here. The simplest entity that has all the
properties of life
 Tissues - made of groups of similar cells that carries out a
particular function in an organism
 Organs - A structure consisting of two or more tissues that
performs specialized functions within an organism
 Organ systems - have specific functions; are composed of organs
that carries out a particular function in an organism
Chapter 1: Exploring Life
Dr. Nezar Redwan
Life’s hierarchy of organization
 Organism:
 Population:
All the individuals of a species only interbreed with
each other within a specific area
 Community:
The array of organisms (different populations) living in
a particular ecosystem
 Ecosystem:
All the organisms (communities) living in a particular
area
 Biosphere :
All the environments (ecosystems) on Earth that
support life
Chapter 1: Exploring Life
Dr. Nezar Redwan
The Characteristics of Life
2. Metabolism:
Sum of all the chemical reactions in an organism.
Organized synthesis and break down of molecules;
can produce energy to power life processes.
3.
Energy processing:
Acquiring energy and transforming it to a form
useful for the organism through metabolism
4. Motility:
Organisms can move themselves or their parts.
5. Responsiveness:
An ability to respond to environmental stimuli
Chapter 1: Exploring Life
Dr. Nezar Redwan
The Characteristics of Life
6. Regulation:
An ability to maintain an internal environment
consistent with life (Homeostasis) Within The Ranges
Required For Life. Stable internal conditions of pH,
temperature, water balance, etc
7.Development:
Develop from simple to more complex organism.
8. Reproduction:
The ability to perpetuate the species, genes are passed
from parent to offspring; genes control an organism’s
phenotype
Chapter 1: Exploring Life
Dr. Nezar Redwan
The Characteristics of Life
9. Evolution:
Evolution is the process of change that transforms life.
Populations change over time as they adapt to their
environment.
10. Adaptations:
The innate fitness of an organism for its environmental
condition. the environment selects organisms with traits/
that are best suited for an organisms environment
(natural selection). The leopard is an excellent example
of an organism adapted to its environment.
Adaptations are the result of evolution
Chapter 1: Exploring Life
Dr. Nezar Redwan
(2) Regulation
(1) Order
(5) Response to the
environment
(3) Growth and
development
(6) Reproduction
(4) Energy processing
(7) Evolutionary adaptation
‫ا‬
Some important properties of life
Chapter 1: Exploring Life
Dr. Nezar Redwan
Some important properties of life
The environment outside
an organism (a living thing)
frequently changes,
but mechanisms regulate
the organism’s internal
environment, keeping
it within limits that
sustain life
(2) Regulation
For example, a jackrabbit can adjust its body temperature by regulating The
amount of blood flowing through its ears. When the rabbit’s body temperature
rises, more blood flows through the vessel in its ears, allowing excess heat to be
released to the air.
Some important properties of life
Information carried by genes
the units of inheritance that
transmit information from
parents
To offspring – controls the
pattern
of growth and development in
all
organisms, including the
Nile crocodile
(3) Growth and development
Chapter 1: Exploring Life
Dr. Nezar Redwan
Some important properties of life
Organisms take in energy
and transform it in
performing all of life’s
activities
(4) Energy processing
Metabolism
Chapter 1: Exploring Life
Fro example, when this
bear eats the fish, it will
use the chemical energy
stored in the fish
to power its own activities
and chemical reactions
(metabolism)
Dr. Nezar Redwan
Some important properties of life
All organisms respond
to environmental stimuli
Fro example, a Venus
flytrap
closes its trap in
response
to the environmental
stimulus
of an insect landing on
it
(5) Response to the environment
Chapter 1: Exploring Life
Dr. Nezar Redwan
Some important properties of life
Organisms reproduce their
own kind, by producing
offsprings.
This emperor
Penguins is protecting its baby.
By reproduction survival of
the specie, not extinction,
is achieved
(6) Reproduction
Chapter 1: Exploring Life
Dr. Nezar Redwan
Some important properties of life
Reproduction underlies the
capacity of populations to
change (evolve) over time
Fro example, the appearance
of the pygmy seahorses
has evolved in the way
that camouflage the animal
in its environment
(7) Evolutionary adaptation
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.2 Living organisms interact with their environments,
exchanging matter and energy
 Life requires interactions between living and
nonliving components
– Photosynthetic organisms provide food and
are called producers
– Others eat plants (or animals that profit from
plants) and are called consumers
– Decomposers: Recycle all organic
materials(Dead plants and animals)
 The nonliving components are chemical
nutrients required for life
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.2 Living organisms interact with their environments,
exchanging matter and energy
 To be successful, an ecosystem must
accomplish two things
– Recycle chemicals necessary for life
– Move energy through the ecosystem
– Energy enters as light and exits as heat
Chapter 1: Exploring Life
Dr. Nezar Redwan
Sunlight ‫أ‬
Ecosystem
Cycling
of
chemical
Nutrients
Producers
(such as plants)
Heat
Chemical energy
Consumers
(such as animals)
)
Decomposers
Heat
The cycling of nutrients
and flow of energy
in an ecosystem
THE PROCESS OF SCIENCE
Scientific Method
Chapter 1: Exploring Life
Dr. Nezar Redwan
Steps in the Scientific Method
Observation
Hypothesis
Experiment
Data Collection
Conclusion
Retest
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.7 Scientists use two main approaches to learn about nature
 Two approaches are used to understand
natural causes for natural phenomena
Discovery based science:
 is results that have been found from actually having
carried out the experiment or investigation.
 uses verifiable observations and measurements to
describe science.
2. Hypothesis- based science:
 is an educated guess by a scientist of what will
happen during an experiment or investigation.
 uses the data from discovery science to explain
science.This requires proposing and testing of
hypotheses.
1.
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.7 Scientists use two main approaches to learn about nature
 There is a difference between a theory
and a hypothesis
– A hypothesis is a proposed explanation
for a set of observations
– A theory is supported by a large and
usually growing body of evidence
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.8 With hypothesis-based science, we pose and test hypotheses

We solve everyday
problems by using
hypotheses
– An example would be the
reasoning we use to answer
the question, “Why doesn’t
the flashlight work?”
– Using deductive reasoning
we realize that the problem
is either the:
(1) bulb or (2) batteries.
– The hypothesis must
be testable
– The hypothesis must
be falsifiable
Observations
Question
‫ر‬
Hypothesis #1:
Dead batteries
Prediction:
Replacing batteries
will fix problem
‫ت‬
Hypothesis #2:
Burned-out bulb
‫يعمل‬
Prediction:
Replacing batteries
will fix problem
Test prediction
Test prediction
‫ا‬
Test falsifies hypothesis
Test does not falsify hypothesis
The Process of Science
 Deductive reasoning:
Draws specific conclusions based on information
(facts)
Inductive reasoning:
Draws general conclusions based on specific
(observations)
Chapter 1: Exploring Life
Dr. Nezar Redwan
The Scientific Method
Steps in the Scientific Method
 Observation
 Question or problem
 Hypotheses
 Testable predictions
 Experiments
 Analyze data
 Conclusions
Chapter 1: Exploring Life
Dr. Nezar Redwan
An example of
hypothesis-based science
Observations
Question
‫ر‬
Hypothesis #1:
Dead batteries
Prediction:
Replacing batteries
will fix problem
‫ت‬
Hypothesis #2:
Burned-out bulb
‫يعمل‬
Prediction:
Replacing batteries
will fix problem
Test prediction
Test prediction
‫ا‬
Test falsifies hypothesis
Test does not falsify hypothesis
The Hypothesis
 A tentative explanation for observations
 Consistent with facts
 Can be tested
 Tests can be repeated by others
 Can be rejected
Chapter 1: Exploring Life
Dr. Nezar Redwan
Testing Predictions by Experiment
 Prediction
 Deductive product of a hypothesis
 Control group
 Closely matches experimental group
 Experimental group
 Differs from control group in 1 variable
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.8 With hypothesis-based science, we pose and test hypotheses
 Another hypothesis:
Mimicry helps protect nonpoisonous
king snakes from predators where
poisonous coral snakes also live
 The hypothesis predicts that predators
learn to avoid the warning coloration of
coral snakes
Chapter 1: Exploring Life
Dr. Nezar Redwan
1.8 With hypothesis-based science, we pose and test hypotheses

Experimentation supports the
prediction of the mimicry hypothesis:

Nonpoisonous snakes that mimic
coloration of coral snakes are attacked
less frequently
 The experiment has a control group
using brown artificial snakes for
comparison
 The experimental group is artificial
snakes with the red, black, and yellow
ring pattern of king snakes
Chapter 1: Exploring Life
Dr. Nezar Redwan
Eastern coral snake (poisonous)
Chapter 1: Exploring Life
Dr. Nezar Redwan
Scarlet king snake (nonpoisonous)
Chapter 1: Exploring Life
Dr. Nezar Redwan
Artificial king snake that was not attacked (left);
artificial brown snake that was attacked by a bear
(right)
Artificial king snake that was not
attacked
Chapter 1: Exploring Life
Artificial brown snake that was
attacked by a bear
Dr. Nezar Redwan
You should now be able to
1. Describe life’s hierarchy of organization
2. Describe living organisms’ interactions with their
environments
3. Describe the structural and functional aspects of cells
4. Explain how the theory of evolution accounts for the unity
and diversity of life
5. Distinguish between discovery science and hypothesis-based
science
6. Describe ways in which biology, technology, and society are
connected
Chapter 1: Exploring Life
Dr. Nezar Redwan
Training Questions (Choose the right answer)
1) Structure fits …………. at all levels of organization in the organism is a basic concept
of biology
a) Species
b) Adaptation
c) Function
d) Strength
e) Response
2) Which of the following is composed of a sequence of nucleotides?
a) DNA
b) Starch
c) Protein
d) RNA
e) A and D are correct choices.
3) A (an)__________ is a group of organisms consisting of only one species that live in
the same place at the same time and producing its own offspring.
a) Organism
b) Population
c) Ecosystem
c) Biosphere
e) Community
4) The middle tier of life hierarchy is characterized by the _______ which is a living
thing.
a) Organ
b) Organism
c) Species
d) Population
e) Ecosystem
5) Living organisms have many __________ that distinguish them from nonliving:
a) Names
b) Attributes
c) Colors
d) Characters (Traits)
e) B And D Are Correct Choices